Dynamic damper

ABSTRACT

Tuned mass adapted to be connected to vehicle body to dampen body vibrations.

United States Patent Gergle et al.

[451 May 16, 1972 DYNAMIC DAMPER Robert G. Gergle, Troy; Zdravko D.Dobrasevic, Detroit, both of Mich.

Inventors:

Assignee: Chrysler Corporation, Highland Park,

Mich.

Filed: Aug. 31, 1970 Appl. No.: 68,702

US. Cl ..267/ 136, 267/8 Int. Cl ..F 16f 1/36 Field of Search ..267/8 D,136, 57.1 R

[56] References Cited UNITED STATES PATENTS 2,081,536 5/1937 Gustafson..267/l 36 3,520,554 7/ 1970 Ravenel ..267/57.l R

Primary Examiner-James B. Marbert Att0rneyTalburtt and Baldwin [5 7]ABSTRACT Tuned mass adapted to be connected to vehicle body to dampenbody vibrations.

4 Claims, 4 Drawing Figures DYNAMIC DAMPER BACKGROUND OF THE INVENTIONThis invention relates to automotive vehicles, and more particularly todevices for preventing vibration induced body noise from becomingobjectionable.

It is known that vehicle body structures vibrate significantly due tomovement of the vehicle along the road. When certain frequencies arereached the noise created by the vibrating body becomes clearly audibleand objectionable to the vehicle occupants. The vibrations are initiallyinduced due to several factors, such as rough road conditions or tirenonconforrnities for example. Other vehicle components, such as thesuspension utilized may contribute to the creation of objectionablevibration noise. The present invention overcomes many of the problemsheretofore presented in this area.

BRIEF SUMMARY OF THE INVENTION Briefly, this invention comprises a tunedmass adapted to be connected to a vehicle body.

One of the primary objects of this invention is to provide a device forpreventing body vibrations in a predetermined range from causingobjectionable noise in the passenger compartment ofa vehicle.

Another object of this invention is to provide a device of the classdescribed for damping vibrations in a vehicle body.

A further object of this invention is to provide a device such asdescribed which may be easily secured to the vehicle body.

Another object of this invention is to provide a device such asdescribed which dampens or tunes out certain noise frequencies caused byrough roads and tire nonuniformities.

Still another object of this invention is to provide a device such asdescribed which is economical in construction and effective inoperation.

Other objects and advantages in this invention will be made apparent asthe description progresses.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings, in whichone of various possible embodiments is illustrated,

FIG. 1 is a perspective view of a vehicle body having a deviceconstructed in accordance with this invention attached thereto, certainparts being broken away for clarity;

FIG. 2 is an enlarged elevation of a device of this invention, certainvehicle parts being shown in section;

FIG. 3 is an enlarged section taken through one of the membersconnecting the device to the vehicle; and

FIG. 4 is an expanded perspective view of a device of this invention.

Like parts are shown by corresponding reference characters through theseveral views of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, avibration damping device I is shown in FIG. 1 attached to a vehicle body3. As shown, the damper l is secured to the vehicle body at a pointrearwardly of the transmission over the drive line or propeller shaft.

The damper includes a tuned metal mass or weight 5 shaped to have twoenlarged end heads 7 and 9 joined by an intermediate thinner section II.The end heads 7 and 9 extend downwardly from the plane of theintermediate section 11 on opposite sides of the drive line housing 13.The weight 5 is tuned to vibrate when subjected to a predetermined rangeof vibratory cycles per second. When the body 3 attempts to vibrate inthe predetermined range the energy attempting to cause the vibrations istransferred to the weight 5 which .vibrates. As described hereafter inmore detail, the transfer of clearly audible and objectionable.

Weight 5 has a plurality of holes 16 therein in which the insulatingassemblies 15 are located. Each insulator 15 comprises a rubberinsulting or isolating bushing assembly 17. Bushing assemblies 17 maytake various forms, but as shown, each includes an outer ring or sleeve19 surrounding a rubber ring 21 and located in a hole 16. The innerperiphery of the ring 21 engages an inner sleeve 23.

An upper plate 25 has a plurality of fasteners, such as bolts thereon,one for each hole 16 which bolts extend down through the body floor 27and the sleeves 23 and through holes in a lower plate 29. Nuts securethe plate 29 to the both and sleeves 23. It will be seen that the weight5 is metallically completely insulated from the body 3 by the rubberrings 19 in bushing assemblies 17.

Naturally the shape and size of the weight 5 may be varied. However, theshape shown is particularly advantageous in that it allows the device tobe installed over a drive line housing.

It has been found that with regard to certain vehicle bodies, a weighton the order of approximately 13 pounds adapted to vibrate when the bodyis subjected to approximately 38-44 cycles/second, will be effective inpreventing the vibratory noises normally accompanying such vibrationfrom entering the passenger compartment. As the body attempts to vibratein such a predetermined vibratory range, the energy is transferredthrough the connectors 15 to the tuned weight 5, which weight vibratesbut does not cause the objectionable noise which would be created by thebody if it were to vibrate in the aforenoted range.

In view of the foregoing, it will be seen that the several objects andother features of this invention are attained.

Although several embodiments of the invention have been disclosed anddescribed, it is apparent that other embodiments and modifications ofthe invention are possible.

We claim:

1. Vibration damping apparatus for a vehicle body comprising a weight,means connecting said weight to said body, said means including aplurality of fasteners, a plurality of resilient insulators located inholes in said weight, said fasteners extending through said insulatorsand said body, said insulators transferring energy from said body tosaid weight when said body is subjected to vibration in a predeterminedvibratory range, and said weight comprising two end head portions, anintermediate section thinner than said end heads joining said end headstogether.

2. Vibration damping apparatus as set forth in claim 1 wherein each ofsaid insulators includes an outer sleeve and an inner sleeve, and arubber ring member between said outer and inner sleeves.

3. Vibration damping apparatus as set forth in claim 1 further includinga lower plate located below said insulators, said fastening extendingthrough said lower plate for connecting the apparatus to said vehiclebody.

4. Vibration damping apparatus as set forth in claim 2 further includinga lower plate, said lower plate having holes therein through which saidfasteners extend, said inner sleeves surrounding said fasteners andcontracting said lower plate adjacent the holes therein.

1. Vibration damping apparatus for a vehicle body comprising a weight,means connecting said weight to said body, said means including aplurality of fasteners, a plurality of resilient insulators located inholes in said weight, said fasteners extending through said insulatorsand said body, said insulators transferring energy from said body tosaid weight when said body is subjected to vibration in a predeterminedvibratory range, and said weight comprising two end head portions, anintermediate section thinner than said end heads joining said end headstogether.
 2. Vibration damping apparatus as set forth in claim 1 whereineach of said insulators includes an outer sleeve and an inner sleeve,and a rubber ring member between said outer and inner sleeves. 3.Vibration damping apparatus as set forth in claim 1 further including alower plate located below said insulators, said fastening extendingthrough said lower plate for connecting the apparatus to said vehiclebody.
 4. Vibration damping apparatus as set forth in claim 2 furtherincluding a lower plate, said lower plate having holes therein throughwhich said fasteners extend, said inner sleeves surrounding saidfasteners and contracting said lower plate adjacent the holes therein.